Many consumer packaging applications employ containers, such as reclosable plastic bags. These bags employ reclosable zippers for locking products within the bags. A typical reclosable zipper includes male and female closures extending along the length of the zipper. In one conventional implementation, the male closure is tree-shaped, with an extended portion arranged to interlock between two extended portions of a mating female closure disposed opposite to the male closure. The closures are interlocked by properly aligning the male and female closures and pressing the closures together along the length of the zipper.
Some types of zippers are opened and closed using sliders. Typical slider zipper designs include a separator or plow-type structure that opens the zipper when the slider travels in one direction along the zipper. The side walls are tapered so as to close the zipper when the slider travels along the zipper in the opposite direction. The slider is adapted to be assembled with the zipper by an endwise assembly or by a relative transverse maneuver. Assembling the slider on the zipper, however, potentially deforms the plastic zipper elements and can compromise the integrity of the seal formed by closing the zipper.
The integrity of the seal can also be compromised by various structural features of the bag. For example, the separator extends through the zipper profile and fits around the base of the profile on the inside of the bag. When a slider having this type of separator is moved to close the bag, a side seal on the side of the bag prevents the slider from traveling off the end of the bag. The side seal holds the zipper closed, thus stopping the separator from moving further. However, the side seal does not allow the slider to sit tightly against it. Consequently, a passageway is formed that can allow the contents of the bag to leak out. Fluids are particularly prone to leaking.